On 09/09/19 4:17 PM, Ramuthevar,Vadivel MuruganX wrote:
> From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
>
> On Intel's Lightning Mountain(LGM) SoC QSPI controller do not auto-poll.
> This patch introduces to properly disable the auto-polling feature to
This patch disables auto polling when direct access mode is disabled
which should be noted in the commit message.
> improve the performance of cadence-quadspi.
How does this improve performance of cadence-quadspi? I would expect HW
auto-polling to be faster than SW polling.
>
> Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
> ---
> drivers/mtd/spi-nor/cadence-quadspi.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> index 73b9fbd1508a..60998eaad1cc 100644
> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> @@ -135,6 +135,8 @@ struct cqspi_driver_platdata {
> #define CQSPI_REG_RD_INSTR_TYPE_DATA_MASK 0x3
> #define CQSPI_REG_RD_INSTR_DUMMY_MASK 0x1F
>
> +#define CQSPI_REG_WR_COMPLETION_CTRL 0x38
> +#define CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL BIT(14)
> #define CQSPI_REG_WR_INSTR 0x08
> #define CQSPI_REG_WR_INSTR_OPCODE_LSB 0
> #define CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB 12
> @@ -471,6 +473,18 @@ static int cqspi_command_write_addr(struct spi_nor *nor,
> return cqspi_exec_flash_cmd(cqspi, reg);
> }
>
> +static int cqspi_disable_auto_poll(struct cqspi_st *cqspi)
> +{
> + void __iomem *reg_base = cqspi->iobase;
> + unsigned int reg;
> +
> + reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
> + reg |= CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL;
> + writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
> +
> + return 0;
> +}
> +
> static int cqspi_read_setup(struct spi_nor *nor)
> {
> struct cqspi_flash_pdata *f_pdata = nor->priv;
> @@ -508,6 +522,11 @@ static int cqspi_read_setup(struct spi_nor *nor)
> reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> reg |= (nor->addr_width - 1);
> writel(reg, reg_base + CQSPI_REG_SIZE);
> +
> + /* Disable auto-polling */
> + if (!f_pdata->use_direct_mode)
> + cqspi_disable_auto_poll(cqspi);
> +
> return 0;
> }
>
Hmmm.. There is no need to disable polling for every read/write
operation. It should be enough to do it once in cqspi_controller_init()
> @@ -627,6 +646,11 @@ static int cqspi_write_setup(struct spi_nor *nor)
> reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> reg |= (nor->addr_width - 1);
> writel(reg, reg_base + CQSPI_REG_SIZE);
> +
> + /* Disable auto-polling */
> + if (!f_pdata->use_direct_mode)
> + cqspi_disable_auto_poll(cqspi);
> +
> return 0;
> }
>
>
--
Regards
Vignesh
